Well I am sure this is obvious and I am going to look silly..... 
Just started playing Rhye's and Fall (CivIV 3.19 version) as Japan and Seoul Independent cities appeared. Cant attack it interact with it in any way. Is it a culture based capture? If I start over and build a city on the spot will I lose the city to a Korean Civ later?
I actually spent 45 minutes searching the forum before posting this.
Thanks in advance for help here!

Just started playing Rhye's and Fall (CivIV 3.19 version) as Japan and Seoul Independent cities appeared. Cant attack it interact with it in any way. Is it a culture based capture? If I start over and build a city on the spot will I lose the city to a Korean Civ later?
I actually spent 45 minutes searching the forum before posting this.
Thanks in advance for help here!